CentOS 7使用Bind/Named配置DNS服务器时反向解析出现NXDOMAIN错误的排查求助

我正在CentOS 7上配置DNS服务器，照着教程一步步操作，但运行dig -x 192.168.40.107时始终收不到应答记录，返回的状态是NXDOMAIN，以下是命令的完整输出：

; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.13 <<>> -x 192.168.40.107
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 24981
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;107.40.168.192.in-addr.arpa.   IN  PTR

;; AUTHORITY SECTION:
168.192.IN-ADDR.ARPA.   86400   IN  SOA 168.192.IN-ADDR.ARPA. . 0 28800 7200 604800 86400

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Mar 09 16:18:26 +04 2023
;; MSG SIZE  rcvd: 111

我到底哪里配置错了？麻烦各位帮忙排查一下，我的所有配置文件内容如下：

/etc/named.conf #

options {
listen-on port 53 { 127.0.0.1; 192.168.40.107; };
#   listen-on-v6 port 53 { ::1; };
directory   "/var/named";
dump-file   "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
recursing-file  "/var/named/data/named.recursing";
secroots-file   "/var/named/data/named.secroots";
allow-query     { localhost; 192.168.40.0/24; };

recursion yes;

forwarders {
8.8.8.8;
8.8.4.4;
};

dnssec-enable yes;
dnssec-validation yes;

bindkeys-file "/etc/named.root.key";

managed-keys-directory "/var/named/dynamic";

pid-file "/run/named/named.pid";
session-keyfile "/run/named/session.key";
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

zone "." IN {
        type hint;
        file "named.ca";
};

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";
include "/etc/named/named.conf.local";

/etc/named/named.conf.local #

zone "okd.local" {
    type master;
    file "/etc/named/zones/db.okd.local"; # zone file path
};

zone "40.168.192.in-addr.erpa" {
    type master;
    file "/etc/named/zones/db.40.168.192"; # 192.168.40.0/24 subnet
};

/etc/named/zones/db.okd.local #

$TTL      604800
@     IN     SOA     okd4-services.okd.local. admin.okd.local. (
                              1     ; Serial
                         604800     ; Refresh
                          86400     ; Retry
                        2419200     ; Expiry
                         604800     ; Nagitave cache TTL
)

; name servers - NS Records
IN      NS      okd4-services

; name servers - A Records
okd4-services.okd.local.        IN     A     192.168.40.107

; OpenShift container plateform cluster - A Records
okd4-bootstrap.lab.okd.local.   IN      A     192.168.40.103
okd4-master1.lab.okd.local.     IN      A     192.168.40.104
okd4-worker1.lab.okd.local.     IN      A     192.168.40.105
okd4-worker2.lab.okd.local.     IN      A     192.168.40.106

; OpenShift internal cluster IPs - A Records
api.lab.okd.local.                              IN      A     192.168.40.107
api-int.lab.okd.local.                          IN      A     192.168.40.107
*.apps.lab.okd.local.                           IN      A     192.168.40.107
etcd-0.lab.okd.local.                           IN      A     192.168.40.104
console-openshift-console.apps.lab.okd.local.   IN      A     192.168.40.107
oauth-openshift.apps.lab.okd.local.             IN      A     192.168.40.107

; OpenShift internal cluster IPs - SRV Records
_etcd-server-ssl._tcp.lab.okd.local     86400   IN     SRV    0     10    2380    etcd-0.lab

/etc/named/zones/db.40.168.192 #

$TTL 604800
@     IN     SOA     okd4-services.okd.local. admin.okd.local. (
                              6     ; Serial
                         604800     ; Refresh
                          86400     ; Retry
                        2419200     ; Expiry
                         604800     ; Nagitave cache TTL
)

; name servers - NS Records
IN      NS      okd4-services.okd.local.

; name servers - PTR Records
107        IN     PTR     okd4-services.okd.local.

; OpenShift container Plateform Cluster - PTR Records
103    IN    PTR    okd4-bootstrap.lab.okd.local.
104    IN    PTR    okd4-master1.lab.okd.local.
105    IN    PTR    okd4-worker1.lab.okd.local.
106    IN    PTR    okd4-worker2.lab.okd.local.
107    IN    PTR    api.lab.okd.local.
107    IN    PTR    api-int.lab.okd.local.

备注：内容来源于stack exchange，提问作者9me